A fast neutron imaging material and a method for preparing the same

Abstract

The application relates to a fast neutron imaging material and a preparation method thereof, and the method comprises the following steps: obtaining a (C 19 H 18 P)2MnBr4 precursor solution; mixing the (C 19 H 18 P)2MnBr4 precursor solution with polyacrylonitrile to obtain a polymer precursor solution; coating the polymer precursor solution on a substrate, and then drying to obtain the fast neutron imaging material. The application provides a new material for fast neutron imaging, and meanwhile improves the spatial resolution of the existing fast neutron imaging material.

Description

Technical Field

[0001] This application relates to the field of fast neutron imaging materials technology, and in particular to a fast neutron imaging material and its preparation method. Background Technology

[0002] Materials photography is a widely used non-destructive testing technique. Neutron imaging mainly includes cold neutron imaging, thermal neutron imaging, and fast neutron imaging. Among these, fast neutrons have a wider energy range and stronger penetrating power. The main method for fast neutron detection is that fast neutrons interact with hydrogen nuclei through elastic scattering to produce recoil protons. These recoil protons then generate electron-hole pairs, which excite a scintillator to emit fluorescence, thus achieving fast neutron detection and imaging. Therefore, in order to achieve effective detection and imaging of fast neutrons, the detection and imaging materials must be rich in hydrogen and have good luminescence properties.

[0003] The most commonly used fast neutron detection imaging materials are mainly composite materials of scintillators and polymers, such as ZnS(Ag):PP and ZnS(Cu):PP. However, existing fast neutron imaging materials struggle to simultaneously absorb and emit fast neutrons, resulting in low spatial resolution for fast neutron imaging. Therefore, if hydrogen-rich units and luminescent units can be coupled and coordinated at the molecular scale, efficient fast neutron imaging holds promise. Summary of the Invention

[0004] This application provides a fast neutron imaging material and its preparation method, thus providing a new material for existing fast neutron imaging.

[0005] In a first aspect, this application provides a fast neutron imaging material and a method for preparing the same, the method comprising:

[0006] Get (C) 19 H 18 P)2MnBr4 precursor solution;

[0007] The (C) 19 H 18 The P)2MnBr4 precursor solution was mixed with polyacrylonitrile to obtain a polymer precursor solution;

[0008] The polymer precursor solution is coated onto a substrate and then dried to obtain a fast neutron imaging material.

[0009] Optionally, the obtained (C) 19 H 18 P)2MnBr4 precursor solution, comprising:

[0010] Based on (C) 19 H 18 The chemical formula of P)2MnBr4 was used to obtain the raw materials;

[0011] The raw material is mixed with an organic solvent to obtain (C 19 H 18 P)2MnBr4 precursor solution.

[0012] Optionally, the raw materials include methyltriphenylphosphine bromide and manganese bromide.

[0013] Optionally, the organic solvent includes one of the following: N,N-dimethylformamide or acetone.

[0014] Optionally, the amount of the organic solvent used is 6 mL to 14 mL, and / or the amount of the polyacrylonitrile used is 0.5 g to 1.5 g.

[0015] Optionally, the amount of polyacrylonitrile used is 0.75g.

[0016] Optionally, the coating thickness is 1000μm to 1500μm.

[0017] Optionally, the polymer precursor solution is coated onto a substrate and then dried to obtain a fast neutron imaging material, comprising:

[0018] The polymer precursor solution is coated onto a substrate and then dried in stages to obtain a fast neutron imaging material; wherein...

[0019] The staged drying process includes: room temperature static drying and vacuum drying.

[0020] Optionally, the time for the room temperature drying is 6h to 24h, and / or the time for the vacuum annealing treatment is 10h to 24h.

[0021] In a second aspect, a fast neutron imaging material is provided, which is prepared by the method described in the first aspect.

[0022] The technical solutions provided in this application have the following advantages compared with the prior art:

[0023] The method for preparing the fast neutron imaging material provided in this application embodiment, (C) 19 H 18 P)2MnBr4 single crystals exhibit strong structural stability and high fluorescence quantum yield, thus demonstrating a good fast neutron response; polyacrylonitrile molecules contain C≡N triple bonds, exhibiting strong polarity and readily reacting with (C) 19 H 18 The bonding ability of P)2MnBr4 single crystal is strong, thus it can bond (C) 19 H 18 P)2MnBr4 single crystal was used as the scintillator material, and polyacrylonitrile was used as the organic matrix. 19 H 18P)₂MnBr₄ single crystals were uniformly dispersed in polyacrylonitrile to form a homogeneous mixture. This mixture was then coated and dried to prepare a fast neutron imaging material with a certain thickness and uniformity.

[0024] It also achieved high spatial resolution for fast neutron imaging. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic flowchart illustrating a method for preparing a fast neutron imaging material provided in an embodiment of this application;

[0028] Figure 2 A (C) provided as an embodiment of this application 19 H 18 Schematic diagram of the crystal structure of P)2MnBr4 single crystal;

[0029] Figure 3 An appearance diagram of a fast neutron imaging material provided in an embodiment of this application;

[0030] Figure 4 An image of a fast neutron imaging material under an ultraviolet lamp, provided as an embodiment of this application;

[0031] Figure 5 A schematic diagram of a fast neutron imaging experimental setup provided in an embodiment of this application;

[0032] Figure 6 This is an imaging plate resolution image of a fast neutron imaging material provided in Embodiment 4 of this application. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0035] In this application, and in the description of this specification, the terms "comprising," "including," etc., mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be a single or multiple.

[0036] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0037] Figure 1 A schematic flowchart illustrating a method for preparing a fast neutron imaging material provided in this application embodiment; please refer to... Figure 1 ,

[0038] This application provides a method for preparing a fast neutron imaging material, the method comprising:

[0039] S1, obtained (C) 19 H 18 P)2MnBr4 precursor solution;

[0040] In some embodiments, the obtained (C) 19 H 18 P)2MnBr4 precursor solution, comprising:

[0041] Based on (C) 19 H 18 The chemical formula of P)2MnBr4 was used to obtain the raw materials;

[0042] The raw material is mixed with an organic solvent to obtain (C 19 H 18 P)2MnBr4 precursor solution.

[0043] In some embodiments, the raw materials include methyltriphenylphosphine bromide and manganese bromide.

[0044] In some embodiments, the organic solvent includes one of the following: N,N-dimethylformamide or acetone.

[0045] In the embodiments of this application, Figure 1 A (C) provided as an embodiment of this application 19 H 18 A schematic diagram of the crystal structure of a P)2MnBr4 single crystal; please refer to [link / reference]. Figure 2 The above (C) 19 H 18 P)2MnBr4 single crystals are formed by introducing large-spaced organic cations (C) into the inorganic framework MnBr2. 19 H 18 P) + Forming a zero-dimensional structure, 1 Mn 2+ The metal ion forms a tetrahedral (MnBr4) with four Cl- halide ions. 2- Inorganic unit, this crystal structure makes (C 19 H 18 P)2MnBr4 single crystals exhibit strong structural stability and high fluorescence quantum yield, thus demonstrating good fast neutron response. The aforementioned (C) 19 H 18 The crystal structure of P)2MnBr4 single crystal belongs to the monoclinic crystal system, with space group P21. (C) 19 H 18In the single crystal structure of P)2MnBr4, the organic cation is methyltriphenylphosphine cation. Using N,N-dimethylformamide and acetone as organic solvents can increase the solubility of the solute, increase the supersaturation of the solution, and promote the formation and growth of crystals. Organic solvents can change the physical properties of the solution, such as viscosity, density, and surface tension, thus affecting the growth rate, shape, and quality of crystals. They can also react chemically with the solute to generate new compounds or change the structure of the solute, thereby obtaining new or optimized crystals. Furthermore, they can act as templates or ligands to form supramolecular assemblies or coordination compounds with the solute, thereby controlling the structure and properties of the crystal. Choosing the wrong organic solvent can have the following adverse effects on crystal growth: it may lead to excessively low or high solubility of the solute, resulting in insufficient or excessive supersaturation of the solution, which affects crystal nucleation and growth; it may lead to unsuitable physical properties of the solution such as viscosity, density, and surface tension, affecting the growth rate, shape, and quality of the crystal; it may lead to adverse changes in the structure or properties of the solute, affecting the structure and performance of the crystal; and it may lead to poor compatibility or dispersibility between the solute and the solvent, affecting the uniformity and stability of the crystal.

[0046] S2, the (C) 19 H 18 The P)2MnBr4 precursor solution was mixed with polyacrylonitrile to obtain a polymer precursor solution;

[0047] In some embodiments, the amount of the organic solvent used is 6 mL to 14 mL, and / or the amount of the polyacrylonitrile used is 0.5 g to 1.5 g.

[0048] In some embodiments, the amount of polyacrylonitrile used is 0.75g.

[0049] In the embodiments of this application, the amount of organic solvent used is limited to obtain the ideal (C 19 H 18 P)2MnBr4 precursor solution, so that (C 19 H 18 P)2MnBr4 single crystals grew well. The amount of polyacrylonitrile was limited to obtain a viscous polymer precursor solution, making (C) 19 H 18 P)2MnBr4 single crystals are dispersed in polyacrylonitrile, and the two have a certain bonding force without affecting (C) 19 H 18 Performance of P)2MnBr4 single crystal. (C 19 H 18P)2MnBr4 single crystal, as a scintillator material, possesses high absorption coefficient, high fluorescence quantum yield, low afterglow time, and low self-absorption, thereby improving the detection and imaging efficiency and signal-to-noise ratio of the scintillator film; polyacrylonitrile, as an organic matrix, exhibits good transparency, flexibility, stability, and adhesion, ensuring the optical performance, mechanical properties, and durability of the scintillator film; (C) 19 H 18 P)2MnBr4 single crystals exhibit good compatibility and dispersibility with polyacrylonitrile, avoiding (C) 19 H 18 The aggregation and precipitation of P)2MnBr4 single crystals affect the uniformity and stability of the scintillator film. For example, the amount of the organic solvent used can be 6 mL, 7 mL, 8 mL, 9 mL, 10 mL, 11 mL, 12 mL, 13 mL, 14 mL, etc.; the amount of polyacrylonitrile used can be 0.5 g, 0.7 g, 0.9 g, 1.0 g, 1.1 g, 1.3 g, 1.5 g, etc.; as one embodiment, the amount of polyacrylonitrile used can be 0.75 g.

[0050] S3. The polymer precursor solution is coated onto the substrate and then dried to obtain a fast neutron imaging material.

[0051] In some embodiments, the coating thickness is 1000 μm to 1500 μm.

[0052] In some embodiments, the polymer precursor solution is coated onto a substrate and then dried to obtain a fast neutron imaging material, comprising:

[0053] The polymer precursor solution is coated onto a substrate and then dried in stages to obtain a fast neutron imaging material; wherein...

[0054] The staged drying process includes: room temperature static drying and vacuum drying.

[0055] In some embodiments, the time for room temperature standing drying is 6h to 24h, and / or the time for vacuum annealing is 10h to 24h.

[0056] In this embodiment, the quartz glass (substrate) is ultrasonically cleaned for 30 minutes in deionized water, acetone, isopropanol, and ethanol, respectively, and then dried with a nitrogen gun. The polymer precursor solution is uniformly coated onto the cleaned quartz substrate and allowed to dry at room temperature for 6–24 hours to obtain an organic-inorganic hybrid metal halide scintillator polymer wet film. The thickness of the coating may balance the absorption efficiency of the material and the transmission efficiency of the scintillator light, thereby optimizing the imaging quality. If the coating thickness is too thin, it may reduce the absorption efficiency of the material, leading to a decrease in the signal-to-noise ratio of the image, and also increasing the requirements for fast neutron imaging, such as quantum efficiency and sensitivity. If the coating thickness is too thick, it will increase the absorption efficiency of the material, but it will also increase the scattering and attenuation of the scintillator light, thereby reducing the spatial resolution and contrast of the image. For example, the coating thickness can be 1000 μm, 1100 μm, 1200 μm, 1300 μm, 1400 μm, 1500 μm, etc. The wet film of the organic-inorganic hybrid metal halide polymer is transferred to a vacuum oven for drying. The pressure inside the oven is reduced to 3–5 Pa and maintained for 10–24 hours to accelerate solvent evaporation, polymer crystallization, and the precipitation of organic-inorganic hybrid metal halide crystals, resulting in a thick film of organic-inorganic hybrid metal halide polymer scintillator (fast neutron imaging material), which can be prepared on a large scale. For example, the above-mentioned room temperature drying time can be 6 h, 10 h, 14 h, 18 h, 22 h, 24 h, etc., and the above-mentioned vacuum drying time can be 10 h, 14 h, 18 h, 22 h, 24 h, etc. Please refer to [link to relevant documentation]. Figure 3 An appearance diagram of a fast neutron imaging material provided in an embodiment of this application; please refer to... Figure 3 This indicates that the surface of the fast neutron imaging material is uniform and flat. Figure 4 An image of a fast neutron imaging material under an ultraviolet lamp, provided as an embodiment of this application; please refer to Figure 4 It can be seen that fast neutron imaging materials have good luminescence properties.

[0057] Based on a general inventive concept, a fast neutron imaging material is provided, which is prepared by the method described in the first aspect.

[0058] The fast neutron imaging material is realized based on the above-described preparation method of the fast neutron imaging material. The specific steps of the preparation method of the fast neutron imaging material can be referred to the above embodiments. Since the fast neutron imaging material adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0059] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0060] Example 1

[0061] A method for preparing fast neutron imaging materials:

[0062] (1) Weigh out 8 mM methyltriphenylphosphine bromide (C) in a molar ratio of 2:1. 19 H 18 Dissolve 4 mM manganese bromide (MnBr2) in 6 mL of N,N-dimethylformyl under magnetic stirring to obtain an organic-inorganic hybrid metal halide scintillator (C). 19 H 18 P)2MnBr4 precursor solution;

[0063] (2) Add 0.5g of polyacrylonitrile (PAN) to the perovskite precursor solution obtained in step (1) and stir to obtain a viscous polymer precursor solution;

[0064] (3) The quartz glass was ultrasonically cleaned in deionized water, acetone, isopropanol and ethanol for 30 minutes, and then dried with a nitrogen gun. The polymer precursor solution obtained in step (2) was uniformly coated on the cleaned quartz substrate to obtain a 1200 μm organic-inorganic hybrid metal halide scintillator polymer wet film, which was then dried at room temperature for 12 h.

[0065] (4) After being dried at room temperature, the material is transferred to a vacuum oven. The pressure inside the oven is reduced to 3 Pa and maintained for 24 hours to accelerate the evaporation of solvent, the crystallization of polymer and the crystallization of organic-inorganic hybrid metal halide, so as to obtain a 680 μm thick film of organic-inorganic hybrid metal halide polymer scintillator (fast neutron imaging material).

[0066] Example 2

[0067] A method for preparing fast neutron imaging materials:

[0068] (1) Weigh out 8 mM methyltriphenylphosphine bromide (C) in a molar ratio of 2:1. 19 H 18 Dissolve 4 mM manganese bromide (MnBr2) in 8 mL of N,N-dimethylformyl under magnetic stirring to obtain an organic-inorganic hybrid metal halide scintillator (C). 19 H 18 P)2MnBr4 precursor solution;

[0069] (2) Add 1.0 g of polyacrylonitrile (PAN) to the perovskite precursor solution obtained in step (1) and stir to obtain a viscous polymer precursor solution;

[0070] (3) The quartz glass was ultrasonically cleaned in deionized water, acetone, isopropanol and ethanol for 30 minutes, and then dried with a nitrogen gun. The polymer precursor solution obtained in step (2) was uniformly coated on the cleaned quartz substrate to obtain a 1500 μm organic-inorganic hybrid metal halide scintillator polymer wet film, and left to stand at room temperature for 14 h.

[0071] (4) After being dried at room temperature, the material was transferred to a vacuum oven. The pressure inside the oven was reduced to 5 Pa and maintained for 22 hours to accelerate the evaporation of solvent, the crystallization of polymer and the crystallization of organic-inorganic hybrid metal halide, so as to obtain a 610 μm thick film of organic-inorganic hybrid metal halide polymer scintillator (fast neutron imaging material).

[0072] Example 3

[0073] A method for preparing fast neutron imaging materials:

[0074] (1) Weigh out 8 mM methyltriphenylphosphine bromide (C) in a molar ratio of 2:1. 19 H 18 Dissolve 4 mM manganese bromide (MnBr2) in 14 mL of N,N-dimethylformyl under magnetic stirring to obtain an organic-inorganic hybrid metal halide scintillator (C). 19 H 18 P)2MnBr4 precursor solution;

[0075] (2) Add 1.5g of polyacrylonitrile (PAN) to the perovskite precursor solution obtained in step (1) and stir to obtain a viscous polymer precursor solution;

[0076] (3) The quartz glass was ultrasonically cleaned in deionized water, acetone, isopropanol and ethanol for 30 minutes, and then dried with a nitrogen gun. The polymer precursor solution obtained in step (2) was uniformly coated on the cleaned quartz substrate to obtain a 1300 μm organic-inorganic hybrid metal halide scintillator polymer wet film, which was then left to stand at room temperature for 10 h.

[0077] (4) After being dried at room temperature, the material is transferred to a vacuum oven. The pressure inside the oven is reduced to 4 Pa ​​and maintained for 24 hours to accelerate the evaporation of solvent, the crystallization of polymer and the crystallization of organic-inorganic hybrid metal halide, so as to obtain a 420 μm thick film of organic-inorganic hybrid metal halide polymer scintillator (fast neutron imaging material).

[0078] Example 4

[0079] A method for preparing fast neutron imaging materials:

[0080] (1) Weigh out 8 mM methyltriphenylphosphine bromide (C) in a molar ratio of 2:1. 19 H 18 Dissolve 4 mM manganese bromide (MnBr2) in 12 mL of N,N-dimethylformyl under magnetic stirring to obtain an organic-inorganic hybrid metal halide scintillator (C). 19 H 18 P)2MnBr4 precursor solution;

[0081] (2) Add 0.75g of polyacrylonitrile (PAN) to the perovskite precursor solution obtained in step (1) and stir to obtain a viscous polymer precursor solution;

[0082] (3) The quartz glass was ultrasonically cleaned in deionized water, acetone, isopropanol and ethanol for 30 minutes, and then dried with a nitrogen gun. The polymer precursor solution obtained in step (2) was uniformly coated on the cleaned quartz substrate to obtain a 1000 μm organic-inorganic hybrid metal halide scintillator polymer wet film, which was then left to stand at room temperature for 12 hours.

[0083] (4) After being dried at room temperature, the material is transferred to a vacuum oven. The pressure inside the oven is reduced to 3 Pa and maintained for 24 hours to accelerate the evaporation of solvent, the crystallization of polymer and the crystallization of organic-inorganic hybrid metal halide, so as to obtain a 190 μm thick film of organic-inorganic hybrid metal halide polymer scintillator (fast neutron imaging material).

[0084] Fast neutron imaging tests were performed on the polymer scintillator thick films (fast neutron imaging materials) prepared in Examples 1-4. Figure 5 A schematic diagram of a fast neutron imaging experimental setup provided in this application embodiment; please refer to... Figure 5 Using a fast neutron imaging system, organic-inorganic hybrid metal halides (C2) were visualized. 19 H 18 Physical imaging of the P)2MnBr4 scintillator film; the test results are shown in Table 1.

[0085] Table 1 Properties of polymer scintillator thick films

[0086] Example 1 0.8 Example 2 1.2 Example 3 0.7 Example 4 0.4

[0087] Through Examples 1-4 and in conjunction with Table 1, a polymer scintillator thick film (fast neutron imaging material) with excellent spatial resolution for fast neutron imaging was prepared. For example, Figure 6For an imaging plate resolution image of a polymer scintillator thick film provided in Embodiment 2 of this application, please refer to [link to embodiment]. Figure 6 According to the line-to-standard calipers, its spatial resolution is approximately 1.2 lpmm. -1 It has high spatial resolution in fast neutron imaging, giving it a clear advantage.

[0088] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A fast neutron imaging material (C 19 H 18 The method for preparing P)2MnBr4 single crystals is characterized by, The method includes: Methyltriphenylphosphine bromide and manganese bromide were mixed with N,N-dimethylformamide or acetone organic solvent to obtain (C 19 H 18 P)2MnBr4 precursor solution; The (C) 19 H 18 The P)2MnBr4 precursor solution was mixed with polyacrylonitrile to obtain a polymer precursor solution; The polymer precursor solution was coated onto a substrate to a thickness of 1000 μm to 1500 μm, followed by staged drying to obtain the fast neutron imaging material (C). 19 H 18 P)2MnBr4 single crystal, the staged drying includes: room temperature static drying and vacuum drying; The (C) 19 H 18 P)2MnBr4 single crystals are formed by introducing large-spaced organic cations (C) into the inorganic framework MnBr2. 19 H 18 P) + Forming a zero-dimensional structure, 1 Mn 2+ The metal ion forms a tetrahedral (MnBr4) with four Cl– halide ions. 2– Inorganic unit.

2. The method according to claim 1, characterized in that, The amount of the organic solvent used is 6 mL to 14 mL, and / or the amount of the polyacrylonitrile used is 0.5 g to 1.5 g.

3. The method according to claim 1, characterized in that, The amount of polyacrylonitrile used is 0.75 g.

4. The method according to claim 1, characterized in that, The time for static drying at room temperature is 6h~24h, and / or the time for vacuum drying is 10h~24h.

5. A fast neutron imaging material, characterized in that, The fast neutron imaging material is prepared by the preparation method according to any one of claims 1 to 4.

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